The stainless steel tubes I ordered 21 days ago finally showed up, so I did some more work on the tether in preperation for the actual tether cable arriving tomorrow. I now have a "waterproof" tether interface box. I reworked the existing tether box to add a gasket material track, potting areas, and two IP-67 rated network and mini USB interface boxes, to hopefully create an IP-IDK (I don't know?) rated box. I did want to see the indicators for the board, so the box contains two tiny holes in the lid with wells intended to be filled with clear epoxy. I think it will work? There will also be a variant of the lid with no holes on the final file release.
The rollers are fitted with the new stainless bits, and I added a "drip loop" velcro bundle to the side of the handle, and totally not because "I accidentally stuck the rollers on the wrong side the first time and this makes it look like I drilled those holes on purpose"
There are 3 additional pieces in the works. A set of secondary spooling thingies to wrap the end of the cable with the cable pull, potted join and seacon connection around outside the main spool, a center "stick something attached to a drill in this hole and turn the drill on to roll the tether up quicker" thing (maybe with gears around the outer edge for a future powered tether feed adaptor? and a small piece around the hole in the back of the frame to facilitate potting around the penetration there. I plan on tossing a couple of extra sections of bluerobotics ROV float foam into the center of the round section to keep the unit floating in the event the potting and sealing fails. Though that will probably only work if most of the tether is paid out at the time it goes in the water. Either way there is room and nothing else is going in there, so why not?
To join the lid to the main frame, it uses 4 m3 bolts and heat set inserts, but the waterproofing will be done with clear silicon or RTV or something along those lines. The RCA balun goes in its container, gets filled with goo, then the lid acts as the finishing segment for the outer gasket channel. The 3 screws that hold the box to the reel also get insert panels and then filled with goo after the box is installed. Then the lid goes on. The mini USB connector is waterproof in its own right, the netowrk cable requires either the available lid that it comes with, or the cable in place. Otherwise it is permeable. but it's the only one I could find.
I do need to figure out a waterproof 2 pin connector of some sort to add a header for a future USBL water gps cable. The plan is to someday build a lower box for that, but as I likely won't have one of those for years, I can ignore it for now.
I'll also be making a 3d printable cable join potting box that will hopefully be much smaller than all the commercially available ones I could find. since a 1 inch diameter cable join for a 1/4" cable is completely overkill in this case.
anyways, here are some updated pictures!
I think it's going to work!